JP2011111989A - Fluid transportation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid transportation device, in which damaging of a tube is prevented and a cam drive force is reduced. <P>SOLUTION: The fluid transportation device 10 includes: the tube 50 having elasticity; a tube restriction part 55c restricting the position of the tube 50; a rotatable cam 20 disposed to be separated from the tube 50; fingers 40-46 disposed between the tube 50 and the cam 20 and moving back and forth toward the tube restriction part 55c along with rotation of the cam 20; and an elastic ring 29 provided on at least either the fingers 40-46 or the cam 20 and deformable in a back and forth direction of the fingers 40-46. The cam 20 has first to fourth cam bodies 21-24 respectively pressing and moving the fingers 40-46 toward the tube restriction part 55c. The first to fourth cam bodies 21-24 are movable in the back and forth direction of the fingers 40-46 by the elastic ring 29. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fluid transport device that transports a fluid by repeatedly closing and releasing a tube with a plurality of fingers.

  As a device that transports liquid at low speed, there is a peristaltic drive type fluid transport device. As one of the peristaltic drive systems, there is one in which a tube having elasticity is sequentially pressed by a plurality of fingers from the upstream side to the downstream side of the fluid by the rotation of the cam drive means. In such a peristaltic fluid transport device, damage to the inside and outside of the tube may occur due to the pressing force of the fingers. If the components including the tube are smaller than the standard size, the tube may not be closed. If it is larger than the standard size, an excessive load will be applied to the cam drive means when the tube is closed. May end up.

  Therefore, it has been proposed to prevent damage to the tube and reduce the cam driving force by providing a pinch finger at the contact portion of the finger with the tube or by providing a convex protrusion (for example, patents). Reference 1).

JP-T-2001-515557 (FIGS. 3 and 4)

  In such a configuration according to Patent Document 1, a pinch finger is further provided on the finger. This finger has a pinch finger and a coiled spring for urging the pinch finger inside the slot of the finger body. In such a configuration, there are many component parts of the finger, and the configuration becomes complicated, which is not suitable for a small-sized fluid transport device that is attached to a living body and injects a chemical solution.

  Further, in the structure in which the convex protrusion is provided on the tube-side contact surface of the finger, the structure is simple, but the effect is limited because the dimension of the finger is fixed.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  [Application Example 1] A fluid transportation device according to this application example includes an elastic tube, a tube restricting portion that restricts the position of the tube, a rotatable cam that is spaced apart from the tube, A plurality of fingers disposed between the tube and the cam and capable of advancing and retreating toward the tube restricting portion according to rotation of the cam; and provided on at least one of the plurality of fingers and the cam; And a plurality of fingers that sequentially press the tube from the upstream side to the downstream side of the fluid to repeatedly close and release the tube and transport the fluid. It is characterized by that.

  According to this application example, at least one of the finger and the cam is provided with an elastic portion that can be deformed in the advancing and retracting direction of the plurality of fingers. With this elastic part, if the finger or cam is arranged closer to the tube restricting part than the standard dimension for tube pressure closure, the components that determine the tube pressure closure amount (crushing amount) including the tube are smaller than the standard dimension. Even in the case, the tube can be reliably closed.

  In addition, if the component is larger than the standard size, the elastic part can be deformed to absorb excessive load, thereby preventing damage inside and outside the tube, and excessively when the tube is closed. No heavy load is applied to the cam, and the drive of the cam does not stop. Further, with such a configuration, the structure can be simplified and downsizing can be realized.

  Application Example 2 In the fluid transportation device according to the application example described above, the cam has a plurality of cam bodies that push each of the plurality of fingers toward the tube restricting portion, and the elastic portion is an elastic member. And it is preferable that the said cam body is movable to the advancing / retreating direction of these fingers by the elastic member.

  In this way, since these cam bodies are constantly pressed toward the tube restricting portion by the elastic member, the tube can be reliably closed when the component is smaller than the standard dimension, The elastic member is deformed and absorbs an excessive load, so that damage inside and outside the tube can be prevented.

  In addition, when the tube is closed, if the tube closing amount (crushing amount) increases from the standard dimension, the load applied to the cam may increase rapidly and the cam may stop driving. However, since the elastic member is deformed to absorb this excessive load and the load can be kept within a certain range, it is possible to prevent the cam from stopping during driving.

  The elastic member may be a common member for each cam body, or may be configured to be provided individually for each cam body.

  Application Example 3 In the fluid transportation device according to the application example described above, it is preferable that the elastic portion is formed in a pressure-closed region of the cam that pushes the tube until the tube is pressure-closed by the plurality of fingers.

  In this way, when the component is larger than the standard size, the elastic portion is deformed to absorb an excessive load. Therefore, the same effect as the above application example can be obtained, and a plurality of elastic portions can be integrally formed on one cam body, so that the number of equipment can be reduced and the structure can be simplified.

  Application Example 4 In the fluid transport device according to the application example described above, the elastic portion is attached to the contact-side end portion of the plurality of fingers with the tube or the contact-side end portion with the cam. A member is preferred.

  In such a configuration, if the finger length including the elastic member is arranged closer to the tube restricting portion than the standard size of the tube pressure closure, the tube can be surely secured even when other components are smaller than the standard size. When the components can be closed, and the components are larger than the standard dimensions, the elastic member can be deformed to absorb excessive load, thereby obtaining the same effect as the structure in which the elastic portion or elastic member is provided on the cam. Can do.

  Further, the structure in which the elastic member is attached to the finger can simplify the configuration of the cam, and is effective in reducing the cost.

  Furthermore, if the elastic member can be attached / detached, when each component part is greatly deviated from the standard dimension, the elastic member having a dimension corresponding to the deviation amount is replaced with an appropriate adjustment of the tube closing amount. You can also.

  Application Example 5 In the fluid transportation device according to the application example, it is preferable that the elastic portion is formed at a contact portion of the plurality of fingers with the tube or a contact portion with the cam.

  Since such a finger can be formed by a two-color molding method of a material having high rigidity and a material having elasticity, the structure can be simplified and the finger can be formed with high accuracy including an elastic portion. Can do. In addition, if the two-color molding method is used, the surface of the abutting portion with the tube or the abutting portion with the cam can be formed more smoothly than when machining by cutting or the like, and the sliding between the tube and the cam is possible. Since the friction can be reduced, the friction load with the tube and the sliding friction load with the cam can be reduced.

FIG. 3 is a plan view showing the main configuration of the fluid transport device according to the first example of the first embodiment. Sectional drawing which shows the APA cut surface of FIG. FIG. 3 is a partial plan view illustrating a configuration of a cam and a state of fluid flow action according to a first example of the first embodiment. The fragmentary sectional view which shows the BB cut surface of FIG. FIG. 6 is a partial plan view showing a configuration of a cam and a state of fluid flow action according to a second example of the first embodiment. The fragmentary sectional view which shows the D-P-D cut surface of FIG. FIG. 9 is a partial plan view illustrating a configuration of a cam and a state of fluid flow action according to a first example of Embodiment 2. The fragmentary sectional view which shows the E-P-E cut surface of FIG. FIG. 9 is a partial plan view illustrating a configuration of a cam and a state of fluid flow action according to a second example of the second embodiment. Sectional drawing which shows the finger which concerns on 1st Example of Embodiment 3. FIG. Sectional drawing which shows the finger which concerns on 2nd Example of Embodiment 3. FIG. Sectional drawing which shows the finger which concerns on 3rd Example of Embodiment 3. FIG. Sectional drawing which shows the finger which concerns on 4th Example of Embodiment 3. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Note that the drawings referred to in the following description are schematic views in which the vertical and horizontal scales of members or portions are different from actual ones for convenience of illustration.
(Embodiment 1 and Example 1)

First, the configuration of the fluid transport device will be described with reference to FIGS. 1 and 2.
FIG. 1 is a plan view showing a main configuration of a fluid transportation device according to a first example of Embodiment 1, and FIG. 2 is a cross-sectional view showing an A-P-A section of FIG. In the fluid transport device 10 according to the present embodiment, the tube unit 11 is slidably mounted in a space formed in the control unit 12, and is detachably fixed using a screw 90 so as to be pressed against the control unit 12 by a fixing frame 13. Configured.

The tube unit 11 includes a reservoir 14 that stores fluid, an elastic tube 50, a plurality of fingers 40 to 46, and a first tube frame 55 and a second tube frame 56 that store these.
In the present embodiment, the reservoir 14 and the tube 50 are exemplified as a structure formed integrally by a hollow molding method, and both are made of an elastic material.

  The tube 50 is mounted in a tube guide groove 55 b formed in the first tube frame 55. A part of the tube guide groove 55 b is formed in an arc shape from the rotation center P of the cam 20 in a state where the tube unit 11 is mounted on the control unit 12. This arc formation area is a pressure-closed area of the tube 50 by the fingers 40 to 46. The outlet portion 53 of the tube 50 extends through the tube unit 11 and the fixed frame 13 to the outside.

  The fingers 40 to 46 are arranged radially at equal intervals from the rotation center P of the cam 20. The fingers 40 to 46 are inserted into finger guide grooves 55 a formed in the first tube frame 55. Since each of the fingers 40 to 46 has the same shape, the finger 43 will be described as an example (see FIG. 2).

  The finger 43 includes a rod-shaped shaft portion 43a, a tube pressing portion 43b formed in a bowl shape at one end portion of the shaft portion 43a, and a cam contact portion 43c formed in a hemispherical shape at the other end portion. In this embodiment, it is made of a metal material. The tube pressing portion 43b protrudes into the tube guide groove 55b and close to the tube 50, and the cam contact portion 43c protrudes from the tube unit 11 to a position close to the cam 20.

  The fingers 40 to 46 are located between the tube 50 and the cam 20, and can advance and retreat from the direction of the rotation center P of the cam 20 toward the tube restricting portion 55 c that is the outer side wall of the tube guide groove 55 b. FIG. 2 shows a state in which the finger 43 press-closes the fluid flow part 51 of the tube 50.

  The present embodiment is a fluid transport device suitable for being attached to a living body and injecting a chemical into the living body. For example, the outer diameter of the tube 50 is about 1 mm to 2 mm, and the outer diameter of the cam 20 is 7 mm to 7 mm. It can also be applied to a small transport device of about 10 mm.

  The reservoir 14 is provided with a septum 95. One end of the septum 95 is disposed so as to be seen from the fixed frame 13 and is configured to be replenished with a chemical solution.

  The control unit 12 includes a cam 20, a transmission wheel 110, a rotor 120, a vibrating body 130 as a drive source, a power source (not shown), a control circuit that controls the driving of the vibrating body 130, and these. The first machine casing 15 and the second machine casing 16 to be held are configured.

  The cam 20 includes a cam axle 25, a cam gear 26 fixed to the cam axle 25, a cam guide shaft 27, an elastic ring 29 as an elastic member fitted to the shaft portion 27a of the cam guide shaft 27, and an elastic member. The first cam body 21, the second cam body 22, the third cam body 23, the fourth cam body 24 mounted on the outer peripheral portion of the ring 29, and the cam body holding that restricts the movement of these cam bodies in the thickness direction. And is supported by the first machine casing 15 and the second machine casing 16. The elastic ring 29 is preferably made of a rubber material.

  The transmission wheel 110 includes a transmission axle 111 on which a pinion 113 is formed, and a transmission gear 112 fixed to the transmission axle 111, and is supported by the first machine casing 15 and the second machine casing 16. Yes.

  The rotor 120 includes a rotor shaft 121 and a pinion 122 fixed to the rotor shaft 121, and is supported by the first machine casing 15 and the second machine casing 16.

  The vibrating body 130 includes a piezoelectric element 131, an arm part 132, and a convex part 133 that comes into contact with the rotor shaft 121. In the vibrating body 130, the arm portion 132 is screwed and fixed to a fixed shaft 135 planted in the first machine casing 15 with a screw or the like. Note that the configuration and driving of the vibrating body 130 are not described because the vibrating body described in Japanese Patent No. 3972608 (see FIGS. 3 and 4) can be adapted.

  A third machine casing 17 is fixed to the outer side (illustrated, lower side) of the first machine casing 15, and a fourth machine casing 18 is fixed to the outer side (illustrated, upper side) of the second machine casing 16. The control unit 12 is configured including 17 and the fourth machine casing 18. The tube unit 11 is slid into the space formed between the third machine casing 17 and the fourth machine casing 18.

  Next, transmission of rotational force from the vibrating body 130 to the cam 20 will be described. The rotor 120 is rotated clockwise by the elliptical vibration of the convex portion 133 of the vibrating body 130, and the rotational force of the rotor 120 is transmitted from the pinion 122 to the cam gear 26 through the transmission gear 112 and the pinion 113 at a predetermined reduction ratio. Then, the cam 20 rotates clockwise.

Next, with reference to FIG. 3 and FIG. 4, details of the configuration of the cam 20 and the fluid flow action according to the first embodiment will be described.
FIG. 3 is a partial plan view showing the configuration of the cam and one state of fluid flow action according to the present embodiment, and FIG. 4 is a partial cross-sectional view showing a BB cut plane of FIG. The cam 20 includes a first cam body 21, a second cam body 22, a third cam body 23, and a fourth cam body 24, and is disposed with a gap in plan view. The first cam body 21 has a release region 21a that does not push the finger, a push region 21b that pushes the finger, and a pressure-closed region 21c that press-closes the fluid flow part 51 of the tube 50 by the finger. is doing.

  Similarly, the second cam body 22 has a release area 22a, a pushing area 22b, and a pressure closing area 22c, and the third cam body 23 also has a releasing area 23a, a pushing area 23b, and a pressure closing area 23c. The fourth cam body 24 also has a release region 24a, a pushing region 24b, and a pressure closing region 24c.

  The first cam body 21 has through holes 21d and 21e, the second cam body 22 has through holes 22d and 22e, the third cam body 23 has through holes 23d and 23e, and the fourth cam body 24 has a through hole. Are provided with through holes 24d and 24e. The first cam body 21, the second cam body 22, the third cam body 23, and the fourth cam body 24 have the same shape.

  The disc portion 27b of the cam guide shaft 27 has cam restricting shafts 32, 34, 36, and 38 for restricting movement of each cam body in the plane direction within a predetermined range, and cam rotating shafts 31, 33, 35, and 37. Has been planted. Since the mounting structure of each cam body to the cam guide shaft 27 is the same, the first cam body 21 will be described as an example.

  The first cam body 21 can be rotated integrally by inserting the through hole 21d in the cam rotating shaft 31 and the through hole 21e in the cam regulating shaft 32. At this time, the fitting between the cam rotation shaft 31 and the through hole 21d sets a small difference in diameter within a range in which the first cam body 21 can rotate. Further, the fitting between the cam regulating shaft 32 and the through hole 21e sets a diameter difference within a range in which the first cam body 21 can rotate within a predetermined range with the cam rotation shaft 31 as a rotation center.

  Each cam body is mounted so as to compress the elastic ring 29, but the first cam body 21 hardly moves because the diameter difference of the through hole 21d with respect to the cam rotation shaft 31 is extremely small. However, since the diameter of the through-hole 21e is larger than the cam restriction shaft 32, the first cam body 21 is moved toward the tube restriction portion 55c around the cam rotation shaft 31 by the elastic force of the elastic ring 29, and The cam restriction shaft 32 and the through hole 21e are rotated (moved) to a position where they abut.

  In this state, the position of the pressure closing region 21c of the first cam body 21 is slightly less than the standard position required for the finger 44 to close the fluid flow portion 51 of the tube 50 in the state of FIG. It protrudes in a direction approaching the portion 55c. This protrusion amount is set to an amount that can be reliably closed by absorbing the dimensional variation of the components that determine the amount of crushing (crushing) of the tube 50. The diameter difference between the cam regulating shaft 32 and the through hole 21e is set larger than the difference between the movement amount of the finger 44 due to the elastic force of the elastic ring 29 and the standard movement amount.

  Here, when the dimensions of the finger 44 and the first cam body 21 including the tube 50 are larger than the standard dimension, the finger 44 closes the fluid flow part 51 and approaches the tube restricting part 55c. Then, the elastic ring 29 is elastically deformed, and the pressure-closed region 21c of the first cam body 21 rotates in the direction of the rotation center P by the diameter difference between the cam regulating shaft 32 and the through hole 21e. Therefore, the finger 44 also moves in a direction away from the tube restricting portion 55c. In addition, the fluid flow part 51 is a state closed by pressure.

When the pushing region 21b of the first cam body 21 configured as described above causes the fingers 45 and 46 to follow, the elastic ring 29 has a pushing force in a direction to press-close the fluid flow portion 51. There is almost no movement of fingers in the area.
(Fluid transportation method)

  Next, a fluid transport method in the present embodiment will be described with reference to FIG. Reference is also made to FIG. The cam 20 is rotated clockwise by the vibrating body 130 at a predetermined reduction ratio. In the state of FIG. 3, the finger 44 press-closes the fluid flow part 51 of the tube 50. Since the fingers 45 and 46 are in the pushing region 21b of the first cam body 21, the fluid flow part 51 is not completely closed.

  Further, since the fingers 41, 42, 43 are in the release region 22 a of the second cam body 22, the fluid flow part 51 is opened. The finger 40 is starting to be applied to the pushing region 22b, and the fluid flow part 51 is still open. A fluid has entered a region of the fluid flow part 51 that is not pressure-closed.

  Further, by rotating the cam 20 clockwise, the fingers 40 to 46 are sequentially closed from the upstream side to the downstream side in the rotational direction of the cam 20, repeatedly repeating the pressure closing to opening to the pressure closing of the fluid flow part 51. Flows in the direction of rotation of the cam 20.

  In this process, when each finger crushes the fluid flow part, the elastic ring 29 is deformed when the claw amount is larger than the standard dimension (that is, when the finger is closer to the tube regulation part 55c than the standard dimension). The cam body moves the finger in a direction away from the tube restricting portion 55c, and makes it possible to keep the pushing pressure of the tube within a certain range.

  The fingers 40 to 46 are pushed back in the direction of the rotation center P by the elastic force of the tubes 50 when the pressing force of each cam body is released after the tubes 50 are closed.

  According to the present embodiment, the cam 20 has the first cam body 21 to the fourth cam body 24 that pushes each of the fingers 40 to 46 toward the tube restricting portion 55c, and an elastic ring 29 as an elastic member. Accordingly, the first cam body 21 to the fourth cam body 24 are constantly pressed toward the tube restricting portion 55c. At this time, the fingers 40 to 46 are protruded by the variation dimension of the constituent parts so as to be closer to the tube restricting portion 55c by the dimension pressed by the elastic ring 29 than the standard dimension capable of closing the fluid flow part 51 of the tube 50. ing.

  Therefore, when the component including the tube 50 is smaller than the standard dimension, the fluid flow part 51 can be reliably closed. When the component is larger than the standard dimension, the elastic ring 29 is deformed to absorb an excessive load. Thus, damage to the inner surface of the fluid flow part 51 and the outer surface of the tube 50 can be prevented.

  When the dimensions of the fingers 44 and the first cam body 21 including the tube 50 are larger than the standard dimensions, the fingers 44 press-close the fluid flow part 51 and still approach the tube restricting part 55c. When the tube 50 is closed and further the amount of crushing (crushing amount) is increased from the standard size, the load applied to the cam 20 increases rapidly, and the cam 20 may stop driving. However, since the elastic ring 29 is deformed and absorbs this excessive load, the load is kept within a certain range, so that the cam 20 can be prevented from stopping during the driving. In addition, from this, it is not necessary to increase the size in order to drive the vibrating body 130 as a drive source with a high torque, and it is possible to reduce the size.

  Further, by using one elastic ring 29 for the first cam body 21 to the fourth cam body 24 as the elastic member, the number of parts can be reduced and the configuration can be simplified. Further, the amount of pressing and the pressing force of each cam body can be made substantially constant.

  Furthermore, the heat conduction between the tube 50 and the cam 20 can be suppressed by using a resin composite material having a low thermal conductivity for the elastic member.

  Further, in the present embodiment, the four first cam bodies 21 to the fourth cam body 24 are provided, but since each of them is common, the manufacturing load of the cam body does not increase and the assemblability is good.

In this embodiment, the elastic ring 29 is used as the elastic member. However, a plate-like elastic member may be provided individually corresponding to the first cam body 21 to the fourth cam body 24.
The material of the elastic member is not limited as long as it has appropriate elasticity.

In this embodiment, the case where the number of cam bodies is four has been described as an example. However, the number of cam bodies may be at least two, or may be five or more.
(Embodiment 1 and Example 2)

  Next, a second example of the first embodiment will be described with reference to the drawings. The second embodiment is characterized in that a plurality of cam bodies are slidable toward the tube restricting portion with respect to the first embodiment described above. Therefore, it demonstrates centering on a different location from 1st Example. Parts having the same function are denoted by the same reference numerals as those in the first embodiment.

  FIG. 5 is a partial plan view showing a configuration of a cam and a state of fluid flow action according to the second example of the first embodiment, and FIG. 6 is a partial cross-sectional view showing a D-P-D cut surface of FIG. is there. The cam 20 includes a first cam body 21, a second cam body 22, a third cam body 23, and a fourth cam body 24 that are disposed with a gap in plan view. The first cam body 21 has a pushing area 21b that pushes the finger, and a pressure closing area 21c that crushes the fluid flow portion 51 of the tube 50 with the finger.

  Similarly, the second cam body 22 has a pushing area 22b and a pressure closing area 22c, the third cam body 23 also has a pushing area 23b and a pressure closing area 23c, and the fourth cam body 24 is also pushed. It has a moving region 24b and a pressure-closed region 24c. The outer peripheral portion 27g of the disk portion 27b of the cam guide shaft 27 corresponds to the release areas 21a, 22a, 23a, 24a of the respective cam bodies of the first embodiment (see FIG. 3).

  The first cam body 21 has a long hole 21f, the second cam body 22 has a long hole 22f, the third cam body 23 has a long hole 23f, and the fourth cam body 24 has a long hole 24f. Of the cam guide shaft 27 (the surface facing the disc portion 27b). The first cam body 21, the second cam body 22, the third cam body 23, and the fourth cam body 24 have the same shape.

  The long holes 21f, 22f, 23f, and 24f are respectively opened radially (that is, in the finger advance / retreat direction) at equal intervals from the rotation center P toward the tube restricting portion 55c. These elongated holes are formed in a rectangular shape within the range of the rotation center P and the pressure-closed regions 21c, 22c, 23c, and 24c of the cam bodies.

  Projecting portions 27c, 27d, 27e, and 27f that face the long holes 21f, 22f, 23f, and 24f, respectively, are formed on the disk portion 27b of the cam guide shaft 27. These protrusions are also rectangular, and are formed radially at equal intervals from the rotation center P toward the tube restricting portion 55c (that is, in the finger advance / retreat direction). The dimensional relationship between the protrusions 27c, 27d, 27e, and 27f and the long holes 21f, 22f, 23f, and 24f is set to a width having a minimum gap in which each cam body can slide, and the length direction of each cam body Sets a slidable length difference within a predetermined range. The dimensional relationship in the length direction will be described by taking the first cam body 21 as an example.

  The first cam body 21 is pressed in the direction approaching the tube restricting portion 55c by the elastic force of the elastic ring 29 and to the position where the protruding portion 27c and the elongated hole 21f abut. In this state, the position of the pressure-closed region 21c of the first cam body 21 is, in the state of FIG. 5, the tube restricting portion 55c than the standard position required for the finger 44 to close-close the fluid flow portion 51 of the tube 50. It protrudes by the variation dimension of the component parts in the direction approaching. The length difference between the protrusion 27c and the long hole 21f is set larger than the difference between the movement amount of the finger 44 and the standard movement amount.

  When the finger 44 press-closes the fluid flow part 51 and further approaches the tube restricting part 55c, the elastic ring 29 is elastically deformed and the first cam body 21 moves in the direction of the rotation center P. Therefore, the finger 44 also moves in a direction away from the tube restricting portion 55c. At this time, the fluid flow part 51 is in a closed state.

  When the pushing region 21b of the first cam body 21 causes the fingers 45 and 46 to follow, the elastic ring 29 has a pushing force to close the fluid flow portion 51. Therefore, the first cam body in this region 21 hardly moves.

  In addition, since the fluid transport action of the fluid transport apparatus 10 according to the second embodiment is the same as that of the first embodiment described above, the description thereof is omitted.

Therefore, in the second embodiment, the same effect as in the first embodiment can be obtained although the configuration of the cam body is different.
(Embodiment 2 / First Example)

  Next, Embodiment 2 will be described with reference to the drawings. The second embodiment is characterized in that each of the cam bodies is configured to be movable in the advancing and retreating direction of the fingers by the elastic ring in the first embodiment described above, but an elastic portion is formed in the cam body. Have. Therefore, it demonstrates centering on a different location from Embodiment 1. FIG. Portions having the same function are denoted by the same reference numerals as those in the first embodiment.

  7 is a partial plan view showing the configuration of the cam and one state of fluid flow action according to the first example of Embodiment 2, and FIG. 8 is a partial cross-sectional view showing the E-P-E cut surface of FIG. is there. The cam 220 includes a cam body 140 that is fixed to the cam wheel shaft 25 and a cam gear 26. The cam body 140 has four cam surfaces in the outer peripheral side surface direction, each of which includes a release area 141, a pushing area 142, a pressure closing area 143, a releasing area 144, a pushing area 145, a pressure closing area 146, and a releasing area. 147, a pushing area 148, a pressure closing area 149, a release area 150, a pushing area 151, and a pressure closing area 152 are formed.

  The pressure-closed region 143 has a peninsula-shaped pushing portion 155, the pressure-closed region 146 has a peninsula-shaped push portion 156, the pressure-closed region 149 has a peninsula-shaped push portion 157, and the pressure-closed region 152 has a A peninsula-shaped pushing portion 158 is formed. These peninsula-shaped pushing parts 155 to 158 form a cantilever-like elastic part and are configured to be able to bend in the advancing and retreating direction of the fingers.

  The pushing portions 155 to 158 are not bent when the fingers 40 to 46 are not pushed, and the tubes 40 to 46 are more restricted than the standard position required to press-close the fluid flow portion 51 of the tube 50. It protrudes by the variation dimension of the component parts in the direction approaching the portion 55c.

  When the dimension of the finger 44 and the cam body 140 including the tube 50 is larger than the standard dimension, the finger 44 closes the fluid flow part 51 and still approaches the tube restricting part 55c. Then, when the finger 44 closes the fluid flow part 51 and approaches the tube restricting part 55c, the pushing parts 155 to 158 are bent in the direction of the rotation center P, and the fingers 40 to 46 are also separated from the tube restricting part 55c. Move in the direction you want to absorb excess load. At this time, the fluid flow part 51 is in a closed state.

  When the fingers 40 to 46 are in contact with the pushing regions 142, 145, 148, and 151 of the cam 220, the pushing portions 155 to 158 are hardly bent or the bending is negligible. There is almost no influence on the pushing amount of the fingers 40 to 46.

  In this way, when the tube 50 and the fingers 40 to 46 are smaller than the standard size, the pushing portions 155 to 158 are not bent and the fingers 44 press-close the fluid flowing portion 51 of the tube 50. Since it protrudes in a direction slightly closer to the tube restricting portion 55c than a necessary standard position, the fluid flow portion 51 can be reliably closed and released, and the tube 50, the fingers 40 to 46, and the cam body 140 are standard. When larger than a dimension, the pushing parts 155-158 as an elastic part deform | transform and absorb an excessive load.

Therefore, the same effect as that of the first embodiment can be obtained. Moreover, since the pushing portions 155 to 158 as elastic portions can be integrally formed on one cam body 140, the number of equipment can be reduced and the structure can be simplified.
(Embodiment 2 / Second Example)

  Next, a second example of the second embodiment will be described with reference to the drawings. The second embodiment is characterized in that the above-described first embodiment forms a cantilever beam as opposed to the cantilever-like pushing portion formed on the cam body as the elastic portion. Have. Therefore, the difference from the first embodiment will be mainly described. In addition, the same code | symbol is attached | subjected to the common part with 1st Example.

  FIG. 9 is a partial plan view showing a configuration of a cam and a state of fluid flow action according to a second example of the second embodiment. The cross-sectional structure is the same as that of the first embodiment (see FIG. 8), and is therefore omitted. The cam body 140 has four cam surfaces in the outer peripheral side surface direction, and each includes a release region 141, a pushing region 142, a pressure closing region 143, a releasing region 144, a pushing region 145, a pressure closing region 146, and a releasing region. 147, a pushing area 148, a pressure closing area 149, a release area 150, a pushing area 151, and a pressure closing area 152 are formed.

  A long hole 160 between the pressure-closed region 143 and the rotation center P, a long hole 161 between the pressure-closed region 146 and the rotation center P, a long hole 162 between the pressure-closed region 149 and the rotation center P, A long hole 163 is formed between the pressure-closed region 152 and the rotation center P. By opening these long holes 160 to 163, the cantilevered elastic portions 165 to 168 extending between the pressure-closure regions and the release regions are formed.

  Here, in a state in which the cam 220 does not push the fingers 40 to 46, the elastic portions 165 to 168 are not bent, and the pressure-closed regions 143, 146, 149, and 152 are the fluid flow of the tube 50 in the fingers 40 to 46. It protrudes by the variation dimension of the component parts in the direction closer to the tube restricting portion 55c than the standard position necessary to press-close the portion 51.

  When the fingers 40 to 46 close the fluid flow part 51 by the pressure-closed regions 143, 146, 149, and 152 and further approach the tube restricting part 55 c, the elastic parts 165 to 168 are bent in the rotation center P direction, The fingers 40 to 46 also move in a direction away from the tube restricting portion 55c and absorb an excessive load. At this time, the fluid flow part 51 is in a closed state.

  When the fingers 40 to 46 are in contact with the pushing regions 142, 145, 148, and 151 of the cam 220, the elastic portions 165 to 168 hardly bend or the bending is negligible. There is almost no effect on the pushing amount of 40-46.

Therefore, the same effects as those of the first embodiment can be obtained with the configuration of the second embodiment described above. Further, like the pushing portions 155 to 158 of the first embodiment (see FIG. 7), the pressure closed regions 143, 146, and 149 are formed so as to be continuous with the elastic portions 165 to 168 without protruding in a peninsular shape. , 152 has a good position accuracy.
(Embodiment 3 / First Example)

Next, Embodiment 3 will be described with reference to the drawings. While the first embodiment described above uses the elastic ring 29 as the elastic portion, the third embodiment is characterized in that the finger is provided with an elastic portion. The finger 43 will be described as an example.
FIG. 10 is a cross-sectional view illustrating the fingers according to the first example of the third embodiment. Reference is also made to FIG. The finger 43 includes a shaft portion 43a and a cap-like elastic member 60 attached to one end of the shaft portion 43a.

  The shaft portion 43a has a hemispherical cam contact portion 43c at one end portion and a flange portion 43d at the other end portion. The elastic member 60 is formed of a material having a hardness higher than that of the tube 50, and has sufficient hardness to press-close the tube 50, and has a hardness to deform when further load is applied after the press-closing. is doing.

  The elastic member 60 has an opening 61, and the opening diameter of the opening 61 is set to be smaller than the outer diameter of the flange portion 43d. When the elastic member 60 is attached, the elastic member 60 can be attached by pushing in using the elasticity of the elastic member 60. .

  The total length including the elastic member 60 of the finger 43 is larger than the standard length necessary for press-closing the fluid flow part 51 of the tube 50 when the finger 43 of the first embodiment (see FIG. 3) is the standard length. Is set slightly longer. That is, it is set longer by the variation dimension of the tube 50 and the cam body.

  In this example, the shape of the cam body may be a simple shape in which the elastic portion is removed from the cam body 140 of the second embodiment (see FIGS. 7 and 9). Therefore, the cam body of the first embodiment is replaced with the cam body 140 for description.

  When the finger 43 closes the fluid flow part 51 and approaches the tube restricting part 55c, the elastic member 60 is deformed in the axial direction and absorbs an excessive load. At this time, the fluid flow part 51 is in a closed state.

  Note that, when the finger 43 is in contact with the pushing region 142 of the cam body 140, the elastic member 60 hardly deforms or the deformation is negligible, so that the pushing amount of the finger 43 is hardly affected.

  Therefore, when the component is smaller than the standard dimension, the elastic member 60 is not deformed and is set longer by the variation dimension of the tube 50 and the cam body 140, so that the fluid flow part 51 is reliably closed and opened. If the amount of crushing (crushing amount) is larger than the standard dimension, the elastic member 60 is deformed to absorb the overload.

  Therefore, the same effect as in the first and second embodiments can be obtained. Further, the cam body 140 can be formed of a single plate member, the shape is simplified because the elastic member 60 is simply attached to the fingers, the number of equipment can be reduced, and the structure can be simplified. Contributes to cost reduction.

Moreover, if the elastic member 60 is formed of a rubber-based material by an injection molding method, there is an effect that damage to the outer surface of the tube 50 can be suppressed.
(Embodiment 3 and second embodiment)

  Next, a second example of the third embodiment will be described with reference to the drawings. Since the shape of the elastic member in the second embodiment is different from that of the first embodiment described above, differences from the first embodiment (see FIG. 10) will be described. In addition, the same code | symbol is attached | subjected to the common part with 1st Example.

  FIG. 11 is a cross-sectional view illustrating the finger according to the second embodiment, and illustrates the finger 43. Reference is also made to FIG. In the elastic member 60, a gap 62 is formed between the opening 61 and the flange 43d in a state of being attached to the flange 43d. Then, the end surface of the elastic member 60 is slightly convex.

  The total length including the elastic member 60 of the finger 43 is larger than the standard length necessary for press-closing the fluid flow part 51 of the tube 50 when the finger 43 of the first embodiment (see FIG. 3) is the standard length. Is set slightly longer. That is, it is set longer by the variation dimension of the tube 50 and the cam body 140.

  When the finger 43 closes the fluid flow part 51 and approaches the tube restricting part 55c, the elastic member 60 is deformed in the axial direction and absorbs an excessive load. At this time, the fluid flow part 51 is in a closed state.

  Note that, when the finger 43 is in contact with the pushing region 142 of the cam body 140, the elastic member 60 hardly deforms or the deformation is negligible, so that the pushing amount of the finger 43 is hardly affected.

  Therefore, when the amount of crushing (crushing amount) of the fluid flow part 51 is the standard dimension or smaller than the standard dimension, the elastic member 60 is not deformed and is set longer by the variation dimension of the tube 50 and the cam body 140. Therefore, the fluid flow part 51 can be reliably closed and opened. When the amount of crushing (crushing amount) is larger than the standard dimension, the elastic member 60 is deformed to absorb an excessive load.

Therefore, the same effect as in the first and second embodiments can be obtained. In addition, since the gap 62 is provided between the elastic member 60 and the flange portion 43d, there is an effect that the response speed becomes faster than when the elastic member 60 is simply compressed and deformed against a sudden overload. This also has the effect of expanding the material options for the elastic member 60.
(Embodiment 3 and Example 3)

  Next, a third example of the third embodiment will be described with reference to the drawings. The third example is characterized in that an elastic member is mounted on the cam contact side of the finger, compared to the first and second examples of the third embodiment described above. Differences from the first embodiment (see FIG. 10) and the second embodiment (see FIG. 11) will be described. In addition, the same code | symbol is attached | subjected to the common part with 1st Example and 2nd Example.

  FIG. 12 is a cross-sectional view illustrating the finger according to the third embodiment, and illustrates the finger 43. Reference is also made to FIG. The finger 43 includes an elastic member 70 that is mounted on the cam contact side end of the shaft portion 43a, and a tube pressing portion 43b that is formed on the finger contact side end.

  The elastic member 70 includes a hemispherical cam contact portion 71 and a shaft portion 72, and the shaft portion 72 is inserted into a hole portion 43e formed in the shaft portion 43a. The tube pressing portion 43b has the same shape as the tube pressing portion 43b of the first embodiment (see FIG. 2).

  The total length including the cam contact portion 71 of the elastic member 70 of the finger 43 is used to press-close the fluid flow portion 51 of the tube 50 when the finger 43 of the first embodiment (see FIG. 3) is set to the standard length. Is set slightly longer than the standard length required. That is, it is set longer by the variation dimension of the tube 50 and the cam body 140.

  Therefore, when the amount of crushing (crushing amount) of the fluid flow part 51 is the standard dimension or smaller than the standard dimension, the elastic member 70 is not deformed and is set longer by the variation dimension of the tube 50 and the cam body 140. Therefore, the fluid flow part 51 can be reliably closed and released. When the amount of crushing (crushing amount) is larger than the standard dimension, the elastic member 70 is deformed to absorb the overload.

Therefore, the same effect as in the first and second embodiments can be obtained. If the elastic member 70 is formed by an injection molding method, the surface of the cam contact portion 71 can be formed smoothly, and the friction load with the cam body 140 can be reduced.
(Embodiment 3 and Example 4)

  Subsequently, a fourth example of the third embodiment will be described with reference to the drawings. The first to third examples of the third embodiment described above are configured such that the elastic member is inserted into the shaft portion. In the fourth example, the finger is formed on the elastic member on the cam contact surface side with the shaft portion. Are integrally formed by a two-color molding method. The finger 43 will be described as an example.

  FIG. 13 is a cross-sectional view showing an example of a finger according to the fourth embodiment. The finger 43 is formed of a shaft portion 43a and a tube contact portion 80 as an elastic member. The cam contact side end of the shaft portion 43a has a hemispherical cam contact portion 43c, a flange portion 43d formed at the end opposite to the cam contact portion 43c, and a hole formed from the flange portion 43d. Part 43f.

  The shaft portion 43a is formed by a primary mold, and the tube contact portion 80 is formed by a secondary mold. The shaft 43a is a resin having a relatively high hardness, and the tube contact portion 80 is made of a material having elasticity lower than that of the shaft 43a and higher than that of the tube 50.

  The total length of the finger 43 including the tube abutting portion 80 is a standard required to press-close the fluid flow portion 51 of the tube 50 when the finger 43 of the first embodiment (see FIG. 3) is the standard length. It is set slightly longer than the length. That is, it is set longer by the variation dimension of the tube 50 and the cam body 140.

  Therefore, when the amount of crushing (crushing amount) of the fluid flow part 51 is the standard dimension or smaller than the standard dimension, the tube contact part 80 is not deformed and is set longer by the variation dimension of the tube 50 and the cam body 140. Therefore, the fluid flow part 51 can be reliably closed and released. When the amount of crushing (crushing amount) is larger than the standard dimension, the elastic tube contact part 80 is deformed and excessively pressed. Absorb weight.

  Therefore, the same effect as in the first and second embodiments can be obtained. Further, by forming the fingers by a two-color molding method, the total length can be formed with higher accuracy than the two-component fingers described above. Further, since the surfaces of the cam contact portion 43c and the tube contact portion 80 can be formed smoothly, the friction load with the cam body 140 can be reduced, and damage to the outer surface of the tube 50 can be suppressed. effective.

  The cam contact side may be an elastic part, and the tube contact side may be a material having high hardness.

It should be noted that the present invention is not limited to the above-described embodiment, but includes modifications and improvements as long as the object of the present invention can be achieved.
For example, in the above-described embodiment, a configuration is illustrated in which a plurality of fingers are radially arranged on a single cam body, and a tube bent in an arc shape is closed with fingers. The present invention can also be applied to a fluid transporting device having a configuration in which a plurality of fingers are arranged along a tube and a plurality of cam bodies corresponding to the number of fingers are provided.

  The present invention is a fluid transport device that can be miniaturized and is optimal for injecting a chemical into a living body while being attached to a living body. However, the present invention can be used not only for fluids but also for transporting gases and highly viscous liquids. . In particular, it can be used in various situations where it is required to transport a small amount of fluid with high accuracy.

  DESCRIPTION OF SYMBOLS 10 ... Fluid transport apparatus, 20 ... Cam, 21-24 ... Cam body, 29 ... Elastic ring, 40-46 ... Finger, 50 ... Tube, 55c ... Tube control part.

Claims (5)

A tube having elasticity, a tube restricting portion for restricting the position of the tube,
A rotatable cam disposed apart from the tube;
A plurality of fingers disposed between the tube and the cam and capable of advancing and retracting toward the tube restricting portion according to the rotation of the cam;
An elastic portion provided on at least one of the plurality of fingers and the cam, and deformable in the advancing and retreating direction of the plurality of fingers;
Have
The fluid transport device, wherein the plurality of fingers sequentially press the tube from the upstream side to the downstream side of the fluid and transport the fluid by repeatedly closing and releasing the tube. The cam has a plurality of cam bodies that push each of the plurality of fingers toward the tube restricting portion,
The elastic part is an elastic member,
The fluid transport device according to claim 1, wherein the cam body is movable in the advancing / retreating direction of the plurality of fingers by the elastic member.   2. The fluid transport device according to claim 1, wherein the elastic portion is formed in a pressure-closed region of the cam that is pushed until the tube is pressure-closed by the plurality of fingers.   2. The fluid according to claim 1, wherein the elastic portion is an elastic member attached to a contact side end portion of the plurality of fingers with the tube or a contact side end portion with the cam. Transport equipment.   2. The fluid transport device according to claim 1, wherein the elastic portion is formed at a contact portion of the plurality of fingers with the tube or a contact portion with the cam.

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